Sumitomo U101153 Mechanics Drill Bit 25/64 in Carbide

Product Description

The SUMITOMO U101153 is a solid carbide mechanics drill bit designed for high-performance drilling in demanding industrial and manufacturing environments. It measures 25/64 inch (9.92 mm) in diameter with a 135-degree split-point tip that self-centers on contact and reduces thrust force. The overall length is 4.1339 inches with a flute length of 2.3622 inches. The TiAlCr/TiSi dual-layer coating provides oxidation resistance and hardness at elevated cutting temperatures. This bit is intended for professional machinists and tool-and-die technicians running production drilling operations on CNC or manual drill presses.

This drill bit is rated for use in cast iron, non-ferrous metals, stainless steel, and general steel stock. The MDW-GS4 series geometry is engineered for high-performance cutting where surface finish and hole accuracy are critical. Typical applications include production machining, fixture building, and precision hole-making in job shop and manufacturing floor environments where solid carbide tooling is specified to meet tight tolerance requirements.

Key Features

• 25/64 inch (9.92 mm) diameter with matching shank diameter of 0.3906 decimal inch for direct chuck mounting
• 135-degree point angle reduces walking and lowers entry thrust on hard materials
• Solid carbide construction provides rigidity and edge retention beyond high-speed steel alternatives
• TiAlCr/TiSi coating improves heat and oxidation resistance for extended tool life in abrasive materials
• Tapered web configuration supports chip evacuation and reduces core buildup during deep passes
• MDW-GS4 series mechanics length for use in standard drill chucks without stub or extended reach tradeoffs

Compatibility

Rated for use in cast iron, non-ferrous metal, stainless steel, and steel workpiece materials corresponding to material codes H, K, M, N, P, and S. Compatible with standard drill chucks accepting a 0.3906 decimal inch round shank.

Installation Notes

This bit is installed by qualified machinists or tool technicians on CNC machining centers, manual drill presses, or hand-held drilling equipment with adequate chuck capacity. Secure the shank fully in the chuck and verify runout before cutting. No coolant-through capability is present on this bit, so external coolant or cutting fluid application is recommended when drilling stainless steel or cast iron to manage heat buildup. Inspect the cutting edge for chipping or wear before each use, as solid carbide is brittle and susceptible to breakage if run with a damaged tip or excessive lateral load.